<template>
    <div>
        <router-link 
          tag="div" 
          to="/" 
          class="header-abs"
          v-show="showAbs"
        >
            <div class="iconfont header-abs-back">&#xe624;</div>
        </router-link>
        <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
            <router-link to="/">
                <div class="iconfont header-fixed-back">&#xe624;</div>
            </router-link>
            景点详情
        </div>
    </div>
</template>

<script>
export default {
    name:'DetailHeader',
    data () {
        return {
            showAbs:true,
            opacityStyle:{
                opacity:0
            }
        }
    },
    methods: {
        handleScroll () {
            const top = document.documentElement.scrollTop
            if (top > 60) {
                let opacity = top / 140
                opacity = opacity > 1 ? 1 : opacity
                this.opacityStyle = {opacity}
                this.showAbs = false
            } else {
                this.showAbs = true
            }
        }
    },
    activated () {
        window.addEventListener('scroll',this.handleScroll)
        console.log(1)
    },
    deactivated () {
        window.removeEventListener('scroll',this.handleScroll)
    }
}
</script>

<style lang="stylus" scoped>
@import '~styles/varibles.styl';
.header-abs
  position absolute
  left .2rem
  top .2rem
  width .8rem
  height .8rem
  line-height .8rem
  border-radius .4rem
  text-align center
  background-color rgba(0,0,0,.8)
  .header-abs-back
    color #ffffff
    font-size .4rem
.header-fixed
    z-index 2
    position fixed
    top 0
    left 0
    right 0
    height $headerHeight
    line-height $headerHeight
    text-align center
    color #fff
    background $bgColor
    font-size .32rem
    .header-fixed-back
        position absolute
        top 0
        left 0
        width .64rem
        text-align center
        font-size .4rem
        color #fff
</style>
